The present invention generally relates to soil sampling methods commonly utilized in agricultural systems and the like, and more particularly to a method and apparatus for collecting and analyzing soil chemistry information from a tract of land utilizing geo-referenced soil sampling.
In modern agricultural systems utilizing precision farming techniques, it is often advantageous to base the application of agricultural products such as seed, fertilizer, lime, and the like on soil chemistry analysis results. Typically, soil chemistry analysis involves the collection of a number of soil samples from a tract of land such as a field or the like. These samples may be analyzed in a soil chemistry laboratory yielding results that may be used by the farmer to generate product application plans.
A common method of soil sampling involves randomly collecting a number of soil samples from a field which are then bulked and mixed thoroughly. A single sub-sample is removed and sent to a soil chemistry laboratory for analysis yielding average soil chemistry results for the entire field. However, this random sample approach has proven to be somewhat limited in its usefulness because it does not indicate areas of high or low yield potential within the field. Consequently, some areas of a field may receive more product than required resulting in waste and unnecessary pollution while other areas may receive less than needed resulting in a reduced yield.
Another method, "Grid Sampling," allows farmers to acquire more accurate information about soil chemistry variation within a field. Two basic methods of grid sampling are known to the art: grid cell sampling and grid point sampling. Grid cell sampling is a process whereby an imaginary grid is laid over a field to determine appropriate locations from which to collect soil samples. Typically, a number of soil samples may be taken randomly from within each grid cell, bulked and mixed. A sub-sample is taken from the bulked samples and sent to a soil chemistry laboratory for testing. Similarly, grid point sampling begins with the generation of a grid to determine locations for collection of soil samples. However, in grid point sampling, soil samples are not taken randomly throughout each grid cell, but instead are collected from within a small radius of each grid intersection. As in grid cell sampling, these samples are bulked, producing a single sample for each grid intersection.
After analysis, a soil chemistry variability map may be generated for the field to aid the farmer in creating a product application plan. Typically, a soil chemistry map displays variations of one or more soil chemistry parameters across the field based on values obtained in each grid cell or at each grid intersection. However, for the soil chemistry map to be accurate, the size of each grid must remain relatively small. Consequently, many soil samples must be collected creating a large amount of data which must be cross-referenced and analyzed. Further, the location from which each soil sample is collected must be accurately calculated and cross-referenced with the results of the laboratory analysis of that soil sample. Thus, it would be advantageous to provide a method and apparatus employing a system approach for collecting and analyzing soil chemistry information from a tract of land utilizing geo-referenced soil sampling.